I can't believe people are pretending to be outraged about something so boring. Oh no, a forum admin trolled a user in a troll subreddit, qué horror!
The thread he changed the comments in was filled with users literally accusing multiple innocent people of being pedophiles who ate children, but sure, it's a bridge too far to change the user tag of comments literally threatening him rather than e.g. banning everyone who commented there or reporting the threats to the police which would have been well within his rights!